1. Field of the Invention
This invention relates to an automatic analytical apparatus for effecting quantitative analysis of a given substance contained in a sample such as blood, urine or the like.
2. Description of the Prior Art
Various kinds of automatic analytical apparatus for measuring the reaction speed of a sample and effecting quantitative analysis of a given substance contained therein have heretofore been proposed. In one of the conventional automatic analytical apparatus, provision is made of two photometric means distant apart from each other and arranged along a reaction line of a sample to be carried at a given period. A difference between absorbancies measured by these two photometric means is detected to measure the reaction speed of the sample. Then, the quantitative analysis of a desirous substance contained in the sample is effected on the basis of the reaction speed thus measured. However, the use of these two photometric means for the purpose of obtaining the change in absorbancy measured by each photometric means provides the disadvantage that the characteristic of a photometric optical system comprising a light source, photoelectric converting element or the like must be adjusted such that the characteristic of the photometric optical system of one of the photometric means is equal to that of the other photometric means, and as a result, each photometric means is complex in construction, and that the use of the two photometric means makes the apparatus as a whole large in size and expensive.
Another automatic analytical apparatus which makes use of a centrifuge system for the purpose of effecting a plurality of photometric operations of the same sample by means of the same photometric means has also been proposed. This conventional apparatus is provided with a disc rotor having a plurality of sets of depressions and a sample is delivered from a delivering means into the depression and then the disc rotor is driven by a centrifuge. After a lapse of several seconds, the sample is transferred through respective holes provided at the outside wall of the depression to the photometric means where the plurality of photometric operations of the sample are effected. But, such apparatus has the disadvantage that the disc rotor must be replaced by a new one everytime the photometric operation is effected and hence is troublesome in operation, and that it is impossible to simultaneously measure a number of items.